Solid state battery

Abstract

To provide a solid battery having improved energy density.SOLUTION: A solid battery has a first current collector layer, a first active substance layer, a separator layer, a second active substance layer, a second current collector layer, and an insulation layer in this order, wherein the first current collector layer winds a laminate of the first active substance layer, the separator layer, the second active substance layer, the second current collector layer, and the insulation layer so as to include the laminate, is joined to the laminate at a position overlapping the surface in a lamination direction of the laminate and forms an exterior body.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to solid-state batteries. [Background technology]

[0002] Patent Document 1 discloses a positive electrode-side sheet body including a first metal foil layer, a positive electrode active material layer laminated on a partial region of one surface of the first metal foil layer, a first thermoplastic resin layer provided in a peripheral portion of the one surface of the first metal foil layer where the positive electrode active material layer is not formed, and a first insulating resin film layer laminated on the other surface of the first metal foil layer; a negative electrode-side sheet body including a second metal foil layer, a negative electrode active material layer laminated on a partial region of one surface of the second metal foil layer, a second thermoplastic resin layer provided in a peripheral portion of the one surface of the second metal foil layer where the negative electrode active material layer is not formed, and a second insulating resin film layer laminated on the other surface of the second metal foil layer; and a separator disposed between the negative electrode side sheet body, the positive electrode active material layer being disposed between the first metal foil layer and the separator, the negative electrode active material layer being disposed between the second metal foil layer and the separator, a first thermoplastic resin layer of the positive electrode side sheet body and a second thermoplastic resin layer of the negative electrode side sheet body being fused to form a peripheral sealing layer, and the two sheet bodies being laminated together, an electrolyte is sealed between the separator and the positive electrode active material layer, an electrolyte is sealed between the separator and the negative electrode active material layer, and a peripheral portion of the separator penetrates into and engages with a middle portion of an inner surface of the peripheral sealing layer in a thickness direction.

[0003] Patent Document 2 discloses a thin battery comprising a power generating element, two exterior bodies for sealing the power generating element, a positive electrode current collecting terminal connected to a positive electrode current collecting portion of the power generating element and covering at least a portion of at least one of both outer surfaces in the stacking direction of the power generating element, and a negative electrode current collecting terminal connected to a negative electrode current collecting portion of the power generating element and covering at least a portion of at least one of both outer surfaces in the stacking direction of the power generating element, wherein at least the side of the outer periphery of the power generating element on which the positive electrode current collecting portion and the negative electrode current collecting portion are provided is wrapped by one or both of the two folded exterior bodies, a first adhesion is performed in which the two exterior bodies are bonded to both outer surfaces in the stacking direction of the power generating element, and a second adhesion is performed on the outside of the power generating element to bond the two exterior bodies, and the adhesive surface of the first adhesion is wider than the adhesive surface of the second adhesion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-21636 A [Patent Document 2] JP 2013-114929 A Summary of the Invention [Problem to be solved by the invention]

[0005] A solid-state battery having a positive electrode current collector layer, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer in this order is known. There is a demand for improving the areal energy density of such a solid-state battery.

[0006] An object of the present disclosure is to provide a solid-state battery with improved areal energy density. [Means for solving the problem]

[0007] The present inventors have found that the above object can be achieved by the following means: Aspect 1 A solid-state battery comprising a first current collector layer, a first active material layer, an electrolyte layer, a second active material layer, a second current collector layer, and an insulating layer stacked in this order, the first current collector layer is wound so as to enclose a laminate of the first active material layer, the electrolyte layer, the second active material layer, the second current collector layer, and the insulating layer, and the laminates are joined to each other at positions overlapping with a surface of the laminate in a stacking direction to form an exterior body; solid state battery. Aspect 2 2. The solid-state battery of aspect 1, wherein the second current collector layer protrudes to an outside of the exterior body in a direction perpendicular to a winding direction of the first current collector layer. Aspect 3 3. The solid-state battery of claim 1, wherein the first current collector layer is made of metal. Aspect 4 When viewed from the stacking direction of the laminate, The second active material layer is disposed inside the outer periphery of the first active material layer, and a joint portion where the first current collector layers are joined to each other overlaps the entire surface of the second active material layer; The solid-state battery according to any one of aspects 1 to 3. Aspect 5 The laminate has a longitudinal direction and a transverse direction, The first current collector layer is formed by winding the laminate around the longitudinal direction as an axis. The solid-state battery according to any one of aspects 1 to 4. Aspect 6 The solid-state battery according to any one of aspects 1 to 5, wherein, when viewed from the stacking direction of the solid-state battery, the second current collector layer and the second active material layer are disposed inside the outer periphery of the insulating layer. Aspect 7 A solid-state battery comprising a first current collector layer, a first active material layer, an electrolyte layer, a second active material layer, and a second current collector layer stacked in this order, The first current collector layer and the second current collector layer are the laminate including the first active material layer, the electrolyte layer, the second active material layer, and the other current collector layer is wound so as to sandwich the laminate; and the other current collector layer is joined to the other current collector layer via an insulating sealant at a position overlapping a surface of the laminate in the lamination direction to form an exterior body; solid state battery. Aspect 8 8. The solid-state battery of claim 7, wherein the first current collector layer and the second current collector layer are made of metal. Aspect 9: When viewed from the stacking direction of the laminate, The second active material layer is disposed inside the outer periphery of the first active material layer, and a joint portion where the first current collector layers are joined to each other overlaps the entire surface of the second active material layer; 9. The solid-state battery according to embodiment 7 or 8. Aspect 10 The laminate has a longitudinal direction and a transverse direction, the first current collector layer and the second current collector layer are wound around the laminate with the longitudinal direction as an axis. The solid-state battery according to any one of aspects 7 to 9. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a solid-state battery with improved energy density. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a solid-state battery 1 according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view of the solid-state battery 1 according to the first embodiment of the present disclosure taken along line AA in FIG. [Diagram 3] FIG. 3 is a schematic diagram showing a part of the internal structure of the solid-state battery 1 according to the first embodiment of the present disclosure when viewed in the stacking direction. [Figure 4] FIG. 4 is a cross-sectional view of a solid-state battery 2 different from the embodiment of the present disclosure. [Diagram 5] FIG. 5 is a schematic diagram showing a part of the internal structure of a solid-state battery 2 different from the embodiment of the present disclosure, when viewed from the stacking direction. [Figure 6] FIG. 6 is a cross-sectional view similar to the AA cross section of FIG. 1, of a solid-state battery 3 according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the present disclosure. Note that, although the embodiments of the present disclosure will be described below using a lithium ion battery as an example, the solid-state battery of the present disclosure is not limited to a lithium ion battery.

[0011] First Embodiment A solid-state battery according to a first embodiment of the present disclosure is a solid-state battery in which a first current collector layer, a first active material layer, an electrolyte layer, a second active material layer, a second current collector layer, and an insulating layer are stacked in this order, and the first current collector layer is wound so as to enclose the stack of the first active material layer, the electrolyte layer, the second active material layer, the second current collector layer, and the insulating layer, and the first current collector layer is joined to each other at a position overlapping with a surface of the stack in the stacking direction to form an exterior body.

[0012] In the solid-state battery according to the first embodiment of the present disclosure, the first current collector layer is wound around the laminate so as to enclose the laminate of the first active material layer, the electrolyte layer, the second active material layer, the second current collector layer, and the insulating layer, and the laminate is joined to each other at a position overlapping the surface of the laminate in the stacking direction to form an exterior body. That is, in the solid-state battery according to the first embodiment of the present disclosure, the first current collector layer has a structure in which the laminate is wound around the laminate so that the first current collector layer overlaps with the surface of the laminate in the stacking direction. Therefore, the solid-state battery is sealed by joining the portions of the first current collector layer as the exterior body at the overlapping portion of the first current collector layer and at the end portion in the direction perpendicular to the winding direction of the first current collector layer.

[0013] As a result, the solid-state battery according to the first embodiment of the present disclosure does not require a sealant for sealing the solid-state battery with an exterior body to be disposed on the side of the solid-state battery. Therefore, the areas of the first active material layer, the electrolyte layer, and the second active material layer when the solid-state battery is viewed from the stacking direction can be increased, and the areas of the first active material layer, the electrolyte layer, and the second active material layer per area of ​​the solid-state battery product including the exterior body can be increased. In addition, since the first current collector layer also serves as the exterior body, a separate exterior body for covering the solid-state battery is not required.

[0014] Therefore, the solid-state battery according to the first embodiment of the present disclosure has a high areal energy density.

[0015] The area energy density is the capacity per unit area of ​​a solid-state battery, and the larger this value is, the more advantageous it is for making the battery smaller.

[0016] A more specific description will be given with reference to Figs. 1 to 3 relating to a solid-state battery 1 according to the first embodiment of the present disclosure, and Figs. 4 and 5 relating to a solid-state battery 2 different from the embodiment of the present disclosure. Note that Figs. 1 to 3 and Figs. 4 and 5 are not intended to limit the solid-state battery of the present disclosure.

[0017] Fig. 1 is a schematic diagram of a solid-state battery 1 according to a first embodiment of the present disclosure, and Fig. 2 is a cross-sectional view of the solid-state battery 1 according to the first embodiment of the present disclosure taken along line AA in Fig. 1.

[0018] As shown in FIGS. 1 and 2, in the solid-state battery 1 according to the first embodiment of the present disclosure, a negative electrode collector layer 11, a negative electrode active material layer 12, a solid electrolyte layer 13, a positive electrode active material layer 14, a positive electrode collector layer 15, and an insulating layer 16 are laminated in this order. Here, the negative electrode collector layer 11 is wound so as to enclose a laminate 17 of the negative electrode active material layer 12, the solid electrolyte layer 13, the positive electrode active material layer 14, the positive electrode collector layer 15, and the insulating layer 16, and is joined to each other via an adhesive layer 18 at a position overlapping the surface of the laminate 17 in the stacking direction to form an exterior body. The negative electrode collector layer 11 constituting the exterior body is bonded by an adhesive layer 19 at both ends 11a perpendicular to the winding direction. In addition, the positive electrode collector layer 15 protrudes to the outside of the exterior body from a direction perpendicular to the winding direction of the negative electrode collector layer 11. Although not shown, in the portion where the positive electrode collector layer 15 protrudes from the inside to the outside of the outer casing formed from the negative electrode collector layer 11, the positive electrode collector layer 15 and the negative electrode collector layer 11 are bonded to each other by an insulating adhesive layer, or by an adhesive layer with an insulating member interposed between the positive electrode collector layer 15 and the negative electrode collector layer 11.

[0019] The solid-state battery 1 according to the first embodiment of the present disclosure can be used by, for example, connecting at least a portion of the negative electrode current collector layer 11 constituting the exterior body and at least a portion of the positive electrode current collector layer 15 protruding outside the exterior body to an external circuit. Note that it is not essential that the positive electrode current collector layer 15 protrudes outside the exterior body, and for example, the positive electrode current collector layer 15 may be joined to a positive electrode current collector tab inside the exterior body, and the positive electrode current collector tab may protrude outside the exterior body.

[0020] Fig. 3 is a schematic diagram showing a part of the internal structure of the solid-state battery 1 according to the first embodiment of the present disclosure when viewed from the stacking direction. More specifically, Fig. 3 shows the structure of a portion including, from the rear side to the front side of the page, a negative electrode current collector layer 11, a negative electrode active material layer 12, a solid electrolyte layer 13, and a positive electrode active material layer 14.

[0021] As shown in Fig. 3, in the solid-state battery 1 according to the first embodiment of the present disclosure, the exterior body formed by the negative electrode current collector layer 11 is sealed by adhesive layers 18 and 19 at a position (not shown) overlapping the surface of the laminate 17 in the stacking direction and at both ends in a direction perpendicular to the winding direction of the negative electrode current collector layer 11. On the other hand, the exterior body does not need to have adhesive layers disposed at both ends in the winding direction of the negative electrode current collector layer 11 as viewed from the stacking direction. Therefore, the widths of the negative electrode active material layer 12, the solid electrolyte layer 13, and the positive electrode active material layer 14 can be increased in this direction. In addition, since the negative electrode current collector layer 11 also serves as the exterior body, a separate exterior body for covering the solid-state battery is not required.

[0022] Therefore, the solid-state battery 1 according to the first embodiment of the present disclosure has a high area energy density.

[0023] In contrast, as shown in Figures 4 and 5, a solid-state battery 2 different from the embodiment of the present disclosure has a structure in which an anode current collector layer 21, an anode active material layer 22, a solid electrolyte layer 23, a cathode active material layer 24, and a cathode current collector layer 25 are laminated in this order, but when viewed from the stacking direction, the edges are sealed with a sealing member 26. In such a configuration, as shown in Figure 5, when viewed from the stacking direction, the sealing member 26 is disposed so as to surround the anode active material layer 22, the solid electrolyte layer 23, and the cathode active material layer 24. Therefore, compared with the solid-state battery 1 according to the first embodiment of the present disclosure, the widths of the anode active material layer 22, the solid electrolyte layer 23, and the cathode active material layer 24 are smaller.

[0024] In the solid-state battery according to the first embodiment of the present disclosure, it is preferable that the second current collector layer protrudes outside the exterior body in a direction perpendicular to the winding direction of the first current collector layer. By adopting such a configuration, the number of parts such as current collector tabs can be reduced.

[0025] In addition, in the solid-state battery according to the first embodiment of the present disclosure, when viewed from the stacking direction of the laminate, it is preferable that the second active material layer is disposed inside the outer periphery of the first active material layer, and the joint where the first current collector layers are joined to each other overlaps the entire surface of the second active material layer. By disposing the second active material layer inside the outer periphery of the first active material layer, in a state where the first current collector layer is wound, the first current collector layer is less likely to come into contact with the positive electrode active material layer and the positive electrode current collector layer, and internal short circuit is suppressed. In addition, by the joint where the first current collector layers are joined to each other overlapping the entire surface of the second active material layer, for example, when a plurality of solid-state batteries according to the first embodiment of the present disclosure are stacked and restrained in the stacking direction, or when a pressure is applied from the stacking direction during the manufacture of the solid-state battery according to the first embodiment of the present disclosure, bias in the in-plane direction of the second active material layer of the pressure applied to the second active material layer can be suppressed.

[0026] From the viewpoint of further suppressing internal short circuits, it is more preferable that the second current collector layer and the second active material layer are disposed inside the outer periphery of the insulating layer when viewed from the stacking direction of the laminate. If the second active material layer is disposed inside the outer periphery of the insulating layer, the first current collector is less likely to come into contact with the second current collector layer and the second active material layer, in particular with the side surfaces of the second current collector layer and the second active material layer, thereby further suppressing internal short circuits.

[0027] In addition, it is preferable that the laminate has a longitudinal direction and a lateral direction, and the first current collector layer is wound around the longitudinal direction. With this configuration, it is possible to reduce the area of ​​the joint portion of the first current collector required for sealing the solid-state battery, particularly the area of ​​the joint portion at the end portion in the direction perpendicular to the winding direction of the first current collector layer. This makes it possible to reduce the area of ​​the solid-state battery, which is advantageous from the viewpoint of area energy density.

[0028] <First current collector layer> The first current collector layer is wound so as to enclose the laminate of the first active material layer, the electrolyte layer, the second active material layer, the second current collector layer, and the insulating layer, and the layers are joined together at a position overlapping the surface of the laminate in the stacking direction to form an outer casing.

[0029] There are no particular limitations on the material used for the first current collector layer, and any material that can be used as a current collector for a battery can be appropriately used.

[0030] For example, the material used for the first current collector layer may be, but is not limited to, stainless steel (SUS), aluminum, copper, nickel, iron, titanium, carbon, or a conductive resin.

[0031] When the first current collector layer is a negative electrode current collector, the material used for the first current collector layer is preferably copper, and when the first current collector layer is a positive electrode current collector, the material used for the first current collector layer is preferably aluminum.

[0032] The shape of the first current collector layer may be any shape that allows the laminate of the first active material layer, the electrolyte layer, the second active material layer, the second current collector layer, and the insulating layer to be wound so as to enclose the laminate, and the laminates to be joined together at positions overlapping the faces of the laminate in the stacking direction to form an exterior body. Examples of such shapes include, but are not limited to, a foil shape.

[0033] From the viewpoint of forming an exterior body, the first current collector layer is preferably made of a material that is difficult for moisture to permeate, and is particularly preferably made of a metal.

[0034] <First active material layer> The first active material layer is a negative electrode active material layer or a positive electrode active material layer.

[0035] The first active material layer contains an electrode active material, and optionally a solid electrolyte, a conductive additive, and a binder.

[0036] (electrode active material) When the first active material layer is a negative electrode active material layer, the electrode active material is a negative electrode active material.

[0037] The material of the negative electrode active material is not particularly limited, and may be metallic lithium, or may be a material capable of absorbing and releasing metal ions such as lithium ions. Examples of the material capable of absorbing and releasing metal ions such as lithium ions include, but are not limited to, alloy-based negative electrode active materials and carbon materials.

[0038] The alloy-based negative electrode active material is not particularly limited, and examples thereof include Si alloy-based negative electrode active materials and Sn alloy-based negative electrode active materials. The Si alloy-based negative electrode active material includes silicon, silicon oxide, silicon carbide, silicon nitride, and solid solutions thereof. The Si alloy-based negative electrode active material can include elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, and the like. The Sn alloy-based negative electrode active material can include tin, tin oxide, tin nitride, and solid solutions thereof. The Sn alloy-based negative electrode active material can include elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, and the like. Among these, the Si alloy-based negative electrode active material is preferred.

[0039] The carbon material is not particularly limited, and examples thereof include hard carbon, soft carbon, graphite, and the like.

[0040] When the first active material layer is a positive electrode active material layer, the electrode active material is a positive electrode active material.

[0041] The material of the positive electrode active material is not particularly limited. For example, the positive electrode active material may be lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese oxide (LiMn2O4), LiCo 1 / 3 Ni 1 / 3 Mn 1 / 3 O2, Li 1+x Mn 2-x-y M yThe material may be, but is not limited to, a Li-Mn spinel substituted with a different element having a composition represented by O4 (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn).

[0042] (solid electrolyte) The material of the solid electrolyte is not particularly limited, and for example, the solid electrolyte may be a sulfide solid electrolyte, an oxide solid electrolyte, a polymer electrolyte, or the like, but is not limited thereto.

[0043] Examples of sulfide solid electrolytes include, but are not limited to, sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, and argyrodite-type solid electrolytes. Specific examples of sulfide solid electrolytes include Li2S-P2S5-based (Li7P3S 11 , Li3PS4, Li8P2S9, etc.), Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-LiBr-Li2S-P2S5, Li2S-P2S5-GeS2(Li 13 GeP3S 16 , Li 10 GeP2S 12 ), LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li 7-x P.S. 6-x Cl x etc.; or combinations thereof, but are not limited to these.

[0044] An example of an oxide solid electrolyte is Li7La3Zr2O 12、 Li 7-x La3Zr 1-x Nb x O 12、 Li 7-3x La3Zr2Al x O 12 , Li 3x La 2 / 3-x TiO3, Li 1+x Al x Ti 2-x (PO4)3, Li 1+x Al x Ge 2-x (PO4)3, Li3PO4, or Li3+x PO 4-x N x (LiPON), but is not limited to these.

[0045] The sulfide solid electrolyte and the oxide solid electrolyte may be glass or crystallized glass (glass ceramic).

[0046] Examples of the polymer electrolyte include, but are not limited to, polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof.

[0047] (Conductive assistant) The conductive additive is not particularly limited. For example, the conductive additive may be a carbon material such as VGCF (Vapor Grown Carbon Fiber) and carbon nanofiber, a metal material, or the like, but is not limited thereto.

[0048] (Binder) The binder is not particularly limited. For example, the binder may be, but is not limited to, a material such as polyvinylidene fluoride (PVdF), butadiene rubber (BR), polytetrafluoroethylene (PTFE), or styrene butadiene rubber (SBR), or a combination thereof.

[0049] <Solid electrolyte layer> The solid electrolyte layer includes at least a solid electrolyte. In addition to the solid electrolyte, the solid electrolyte layer may include a binder, etc., as necessary. For the solid electrolyte and the binder, the above description of "<First active material layer>" can be referred to.

[0050] <Second active material layer> For the second active material layer, the above description of "<First current collector layer>" can be referred to.

[0051] The first and second active material layers have opposite polarities. That is, if the first active material layer is a negative electrode active material layer, the second active material layer is a positive electrode active material layer. Similarly, if the first active material layer is a positive electrode active material layer, the second active material layer is a negative electrode active material layer.

[0052] <Second current collector layer> The second current collector layer can be formed from the materials described above under "First current collector layer."

[0053] The shape of the second current collector layer is not particularly limited, and examples thereof include a foil shape, a plate shape, a mesh shape, etc. Among these, a foil shape is preferred.

[0054] The first and second current collector layers have opposite polarities. That is, if the first current collector layer is a negative current collector layer, the second current collector layer is a positive current collector layer. Similarly, if the first current collector layer is a positive current collector layer, the second current collector layer is a negative current collector layer.

[0055] Insulating layer The insulating layer is a layer that provides electrical insulation between the first current collector layer and the second current collector layer. The material constituting the insulating layer is not particularly limited as long as it has the necessary insulating properties, and any known material can be used.

[0056] Such a material may be, for example, an insulating resin material, more specifically, a thermoplastic resin such as polyethylene terephthalate (PET), polypropylene (PP), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), polycarbonate (PC), or polyetherimide (PEI), or a rubber such as acrylonitrile butadiene rubber (ABR) or butadiene rubber (BR), or a non-conductive binder such as an epoxy or acrylic binder. Also, such a material may be, for example, an insulating metal oxide, more specifically, alumina, zirconia, calcium oxide, magnesium oxide, or the like. Also, the insulating material may be any combination of the above-mentioned materials.

[0057] When a sulfide solid electrolyte is used as the solid electrolyte, it is particularly preferable to use a material made of a polyimide-based resin, such as Kapton tape.

[0058] <Adhesive layer> The adhesive layer may be made of any material capable of bonding the first current collector layers together, such as a thermoplastic resin such as polypropylene (PP).

[0059] Second Embodiment A solid-state battery according to a second embodiment of the present disclosure is a solid-state battery in which a first current collector layer, a first active material layer, an electrolyte layer, a second active material layer, and a second current collector layer are stacked in this order, and the first current collector layer and the second current collector layer are wound so as to sandwich a laminate of the first active material layer, the electrolyte layer, the second active material layer, and the other current collector layer, and are joined to the other current collector layer at a position overlapping the surface of the laminate in the stacking direction via an insulating adhesive layer to form an exterior body.

[0060] In the solid-state battery according to the second embodiment of the present disclosure, the first current collector layer and the second current collector layer are wound so as to sandwich a laminate of the first active material layer, the electrolyte layer, the second active material layer, and the other current collector layer, and are joined to the other current collector layer via an insulating adhesive layer at a position overlapping the surface of the laminate in the stacking direction to form an exterior body. That is, in the solid-state battery according to the second embodiment of the present disclosure, the first current collector layer and the second current collector layer each have a structure in which a laminate is wound so that the first current collector layer and the second current collector layer overlap at a position overlapping the surface of the laminate in the stacking direction. Therefore, the first current collector layer and the second current collector layer serving as an outer casing are joined to each other at the overlapping portion of the first current collector layer and the second current collector layer and at the ends in a direction perpendicular to the winding direction of the first current collector layer and the second current collector layer, thereby forming a structure that seals the solid-state battery.

[0061] As a result, in the solid-state battery according to the second embodiment of the present disclosure, there is no need to place a sealant for sealing the solid-state battery with an exterior body on the side surface of the solid-state battery.

[0062] Therefore, the areas of the first active material layer, the electrolyte layer, and the second active material layer can be increased when the solid-state battery is viewed from the stacking direction, thereby increasing the volumes of the first active material layer, the electrolyte layer, and the second active material layer per volume of the solid-state battery product including the exterior body. In addition, since the first current collector layer and the second current collector layer also serve as the exterior body, a separate exterior body for covering the solid-state battery is not required.

[0063] Therefore, the solid-state battery according to the second embodiment of the present disclosure has a high areal energy density.

[0064] The area energy density is the capacity per unit area of ​​a solid-state battery, and the larger this value is, the more advantageous it is for making the battery smaller.

[0065] Moreover, in the solid-state battery according to the second embodiment of the present disclosure, a series circuit of solid-state batteries can be easily formed with a small occupying volume by stacking a plurality of solid-state batteries in a stacking direction of the solid-state batteries, i.e., in the stacking direction of the first current collector layer, the first active material layer, the electrolyte layer, the second active material layer, and the second current collector layer.

[0066] Fig. 6 is a cross-sectional view of a solid-state battery 3 according to a second embodiment of the present disclosure, similar to the cross-section AA in Fig. 1. Note that Fig. 6 is not intended to limit the solid-state battery of the present disclosure.

[0067] 6, the solid-state battery 3 according to the second embodiment of the present disclosure is a solid-state battery 3 in which a negative electrode collector layer 31, a negative electrode active material layer 32, a solid electrolyte layer 33, a positive electrode active material layer 34, and a positive electrode collector layer 35 are laminated in this order, and the negative electrode collector layer 31 and the positive electrode collector layer 35 are wound so as to sandwich the laminate of the negative electrode active material layer 32, the solid electrolyte layer 33, and the positive electrode active material layer 34, and the other current collector layer, and are joined to the other current collector layer via an insulating adhesive layer 36 at a position overlapping the surface of the laminate in the stacking direction to form an exterior body. The negative electrode collector layer 31 and the positive electrode collector layer 35 constituting the exterior body are bonded to each other by an adhesive layer at both ends perpendicular to the winding direction.

[0068] The solid-state battery according to the second embodiment of the present disclosure can be used by, for example, connecting at least a portion of the negative electrode current collector layer and the positive electrode current collector layer that constitute the exterior body to an external circuit.

[0069] In addition, in the solid-state battery according to the second embodiment of the present disclosure, when viewed from the stacking direction of the laminate, it is preferable that the second active material layer is disposed inside the outer periphery of the first active material layer, and the joint where the first current collector layers are joined to each other overlaps the entire surface of the second active material layer. Since the second active material layer is disposed inside the outer periphery of the first active material layer, when the first current collector layer and the second current collector layer are wound, the first current collector layer is less likely to come into contact with the positive electrode active material layer and the positive electrode current collector layer, and internal short circuits are suppressed. Furthermore, since the joint where the first current collector layers are joined to each other overlaps the entire surface of the second active material layer, for example, when a plurality of solid-state batteries according to the second embodiment of the present disclosure are stacked and restrained in the stacking direction, or when a pressure is applied from the stacking direction during the manufacture of the solid-state battery according to the second embodiment of the present disclosure, the bias of the pressure applied to the second active material layer in the in-plane direction of the second active material layer can be suppressed.

[0070] In addition, it is preferable that the laminate has a longitudinal direction and a transverse direction, and the first current collector layer and the second current collector layer are wound around the longitudinal direction. With this configuration, it is possible to reduce the area of ​​the joint between the first current collector layer and the second current collector layer required for sealing the solid-state battery, particularly the area of ​​the joint at the end in the direction perpendicular to the winding direction of the first current collector layer and the second current collector layer. This makes it possible to reduce the area of ​​the solid-state battery, which is advantageous from the viewpoint of area energy density.

[0071] For the negative electrode current collector layer, the negative electrode active material layer, the electrolyte layer, the positive electrode active material layer, the positive electrode current collector layer, and the adhesive layer that can be employed in the solid-state battery according to the second embodiment of the present disclosure, reference can be made to the descriptions regarding the solid-state battery according to the first embodiment of the present disclosure. [Explanation of symbols]

[0072] 1~3 solid state battery 11, 21, and 31 negative electrode current collector layers 12, 22, and 32 negative electrode active material layers 13, 23, and 33 Solid electrolyte layers 14, 24, and 34 Positive electrode active material layers 15, 25, and 35 Positive electrode current collector layers 16 Insulating layer 17 Laminate 18, 19, and 36 Adhesive Layers 26 Sealing material

Claims

1. A solid-state battery comprising a first current collector layer, a first active material layer, an electrolyte layer, a second active material layer, a second current collector layer, and an insulating layer stacked in this order, the first current collector layer is wound so as to enclose a laminate of the first active material layer, the electrolyte layer, the second active material layer, the second current collector layer, and the insulating layer, and the laminates are joined to each other at positions overlapping with a surface of the laminate in a stacking direction to form an exterior body; solid state battery.

2. The solid-state battery according to claim 1 , wherein the second current collector layer protrudes to the outside of the exterior body in a direction perpendicular to a winding direction of the first current collector layer.

3. The solid-state battery according to claim 1 , wherein the first current collector layer is made of a metal.

4. When viewed from the stacking direction of the laminate, The second active material layer is disposed inside the outer periphery of the first active material layer, and a joint portion where the first current collector layers are joined to each other overlaps the entire surface of the second active material layer; The solid-state battery according to claim 1 or 2.

5. The laminate has a longitudinal direction and a transverse direction, The first current collector layer is formed by winding the laminate around the longitudinal direction as an axis. The solid-state battery according to claim 1 or 2.

6. 3 . The solid-state battery according to claim 1 , wherein the second current collector layer and the second active material layer are disposed inside an outer periphery of the insulating layer when viewed from a stacking direction of the solid-state battery.

7. A solid-state battery comprising a first current collector layer, a first active material layer, an electrolyte layer, a second active material layer, and a second current collector layer stacked in this order, The first current collector layer and the second current collector layer are the laminate including the first active material layer, the electrolyte layer, the second active material layer, and the other current collector layer is wound so as to sandwich the laminate; and the other current collector layer is joined to the other current collector layer via an insulating sealant at a position overlapping a surface of the laminate in the lamination direction to form an exterior body; solid state battery.

8. The solid-state battery according to claim 7 , wherein the first current collector layer and the second current collector layer are made of metal.

9. When viewed from the stacking direction of the laminate, The second active material layer is disposed inside the outer periphery of the first active material layer, and a joint portion where the first current collector layers are joined to each other overlaps the entire surface of the second active material layer; The solid-state battery according to claim 7 or 8.

10. The laminate has a longitudinal direction and a transverse direction, the first current collector layer and the second current collector layer are wound around the longitudinal direction of the laminate; The solid-state battery according to claim 7 or 8.

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